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Objective The risk of suicide is assessed by identifying the relationship between alcohol-use patterns and suicidal ideation in Korean employees.Methods The study involved 13,858 employees who underwent workplace mental health screening at the Workplace Mental Health Institute of Kangbuk Samsung Hospital over a 6-year period between 2014 and 2019. Analysis was performed separately for Alcohol Use Disorders Identification Test-Korea (AUDIT-K) items related to the frequency/volume of alcohol consumption (items 1 to 3, AUDIT-C) and those regarding alcohol dependence/related problems (items 4 to 10, AUDIT-D/P). Subjects were then classified into three groups on the basis of the presence or absence of clinical depression and suicidal ideation. The groups’ sociodemographic factors and clinical features of depression, anxiety, and alcohol-use patterns were analyzed with a chi-square test as well as one-way analysis of variance, followed by a post hoc test using the Bonferroni correction.Results AUDIT-K and AUDIT-D/P scores were significantly associated with the presence or absence of clinical depression as well as the presence or absence of suicidal ideation (p

Purpose: This study aimed to analyze the alcohol use patterns that may influence suicide attempt in employees who have suicidal ideation.Methods: The 15,199 participants were classified into three groups according to suicide risk severity. Participant scores on the Alcohol Use Disorders Identification Test-Korea (AUDIT-K), subscale for drinking amount/frequency (AUDIT-C, items 1–3), subscale for dependence/related problems (AUDIT-D/P, items 4–10), and other sociodemographic and psychiatric scales were analyzed between the groups using one-way analysis of variance (ANOVA) and the chi-square test, followed by post hoc analysis using the Bonferroni correction.Results: A statistically significant difference between all three groups was observed for AUDIT-D/P scores after post hoc analysis (P < 0.001), indicating an increasing trend for greater suicide risk. This trend was present in both sexes and across all age groups above 30 years old.Conclusion: Alcohol dependence/related problems are significantly associated with suicide attempt among employees. Assessing and preventing suicide risk according to these issues may minimize socioeconomic losses due to suicide.

BACKGROUND AND PURPOSE Managing hydrocephalus in patients with vestibular schwannoma (VS) is controversial. We evaluated the clinical factors associated with hydrocephalus. METHODS Between 2000 and 2019, 562 patients with VS were treated at our institute. We applied endoscopic third ventriculostomy (ETV), external ventricular drainage (EVD), and ventriculoperitoneal (VP) shunts to patients with hydrocephalus. The relationships of patient, tumor, and surgical variables with the hydrocephalus outcome were assessed. RESULTS Preoperative hydrocephalus (Evans ratio ≥0.3) was present in 128 patients. Six patients who received a preresectional VP shunt were excluded after analyzing the hydrocephalus outcome. Seven of the remaining 122 patients had severe hydrocephalus (Evans ratio ≥0.4). Primary tumor resection, VP shunting, ETV, and EVD were performed in 60, 6, 57, and 5 patients, respectively. The hydrocephalus treatment failure rate was highest in the EVD group. Persistent hydrocephalus was present in five (8%) and seven (12%) patients in the primary resection and ETV groups, respectively. Multivariate analysis revealed that severe hydrocephalus, the cystic tumor, and the extent of resection (subtotal resection or partial resection) were associated with hydrocephalus treatment failure. CONCLUSIONS Larger ventricles and a higher cystic portion are predictive of persistent hydrocephalus. We recommend attempting near-total tumor resection in patients with VS.

A new design concept for ion-conducting polymers in anion exchange membranes (AEMs) fuel cells is proposed based on structural studies and conformational analysis of polymers and their effect on the properties of AEMs. Thermally, chemically, and mechanically stable terphenyl-based polymers with pendant quaternary ammonium alkyl groups were synthesized to investigate the effect of varying the arrangement of the polymer backbone and cation-tethered alkyl chains. The results demonstrate that the microstructure and morphology of these polymeric membranes significantly influence ion conductivity and fuel cell performance. The results of this study provide new insights that will guide the molecular design of polymer electrolyte materials to improve fuel cell performance.

Objective The aim of study is to investigate the relationship between serum vitamin D, c-reactive protein (CRP) levels, and anxiety symptoms.Methods Serum vitamin D and CRP levels of 51,003 Korean adult participants were collected retrospectively. Anxiety symptoms were assessed using the Korean version of Beck Anxiety Inventory. Logistic regression was used to estimate the odds ratio (ORs) of anxiety symptoms by serum vitamin D and CRP levels. The regression was adjusted for covariates, and each model was adjusted mutually for vitamin D and CRP levels.Results Compared with sufficient vitamin D levels (≥20 ng/mL), insufficient (10–19.99 ng/mL) and deficient (

Objective Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro. Methods Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1-C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily. Results In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10-20 μg/mL) for 5 days and 4 days in assays of half and total exchange of PBS. Conclusion This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

This study investigates organic pesticide adoption in residential lawn care management, incorporating determinants based on a synthesis of multiple literatures. A mail survey using the Dillman method was conducted in Missouri in 2014 with a random sample of 2000 single-family households (44.1% effective response rate). The data indicate an adoption rate of 17.7% for organic pesticides. This unique dataset also allows us to differentiate distinct non-adopters by familiarity with the practice as well as non-use of any pesticides. Multinomial logit regressions find environmental concerns, awareness of neighbor’s opinions, and gardening behaviors as significant determinants. The effects on relative probability of being an adopter are large: 18 times more likely for people with serious environmental concerns or 5 times more likely for those spending more than 15 hours per month on lawn care.

Numerous confidence estimation methods have been proposed for classification neural networks; however, this problem has not been well addressed for regression neural networks. That is, softmax layers are not available in regression networks and the interpretation of confidence becomes less clear. To alleviate these problems, a simple but effective method is proposed that computes the confidences of regression results. First, the confidence is considered as a scalar value representing relative error‐levels. Then, a mini‐batch based training method based on this interpretation is developed. Precisely, in each mini‐batch, desired outputs for confidence values are assigned by sorting current errors. Experimental results on the loose wheel nut detection problem as well as a simulated example have shown that the proposed method can be successfully applied to regression problems.

Surgery for petroclival meningioma is challenging because cranial nerve preservation during tumor removal can be very complex. For small- to medium-sized tumors, the anatomical relationship between tumor and neurovascular structures can be assessed before surgery. However, in large tumors, cranial nerves usually cannot be seen in preoperative images. The authors present a case of a 65-year-old woman who presented with gait disturbance and hearing loss and was diagnosed with huge retroclival meningioma involving the cavernous sinus, Meckel’s cave, and internal acoustic meatus. In this video, they explain the radiographical, anatomical, and surgical considerations and demonstrate the surgical technique. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21221

Objective The aim of this study is to determine the dose-response relationship between physical activity and anxiety symptoms. Methods We included data of 124,434 participants who had comprehensive health-screening examinations from January 1st, 2012, to December 31st, 2016, in Kangbuk Samsung Hospital, Seoul and Suwon, South Korea. We measured the level of physical activity using the International Physical Activity Questionnaire-short form (IPAQ-SF) and estimated anxiety symptoms using the Beck Anxiety Inventory (BAI). BAI scores of 19 and above were defined as cases. Logistic regression was used to analyze the association between physical activity and BAI-defined anxiety. Furthermore, we assessed whether sex differences might affect the relationship between physical activity and BAI-defined anxiety by stratifying our data. Results Compared with the sedentary group (0-600 METs-min/week), individuals achieving 600-6,000 METs-min/wk had a significantly lower risk of BAI-defined anxiety with a U-shaped relationship in general adults. After stratifying our data by sex, we found that optimal ranges of physical activity were 600-9,000 METs-min/wk for men, but 1,200-3,000 METs-min/wk for women. Conclusion We identified a U- or J-shaped association between physical activity and anxiety symptoms, suggesting an optimal dose and upper limit of physical activity for decreasing anxiety symptoms. Optimal levels and upper limits of physical activity for reducing anxiety symptoms were higher for men than for women.

Physically reinforced short-side-chain perfluorinated sulfonic acid electrolyte membranes were fabricated by annealing and using a porous support. Five types of solution-cast membranes were produced from commercial perfluorinated ionomers (3M and Aquivion (AQ)) with different equivalent weights, annealed at different temperatures, and characterized in terms of ion conductivity, water uptake, and in-plane/through-plane swelling, while the effect of annealing on physical structure of membranes was evaluated by small-angle X-ray scattering and dynamic mechanical analysis. To create a reinforced composite membrane (RCM), we impregnated a polytetrafluoroethylene porous support with 3M 729 and AQ 720 electrolytes exhibiting excellent proton conductivity and water uptake. The electrolyte impregnation stability for the porous support was evaluated using a solvent resistance test, and the best performance was observed for the 3M 729 RCM annealed at 200 °C. Both annealed and nonannealed 3M 729 RCMs were used to produce membrane electrode assemblies, the durability of which was evaluated by open-circuit voltage combined wet–dry cycling tests. The nonannealed 3M 729 RCM survived 5800 cycles, while the 3M 729 RCM annealed at 200 °C survived 16 600 cycles and thus exhibited improved mechanical durability.

Objective The aim of this study was to identify work stress associated with the development of suicidal ideation with a focus on gender and age differences among Korean employees. Methods The data of 95 356 healthy employees aged >18 years who had undergone at least two comprehensive health examinations at Kangbuk Samsung Hospital Health Screening Center, South Korea, were analyzed. Risk of suicidal ideation was assessed using a self-reported questionnaire examining suicidal ideation during the past year. Work stress was measured using the Korean Occupational Stress Scale-Short Form. A Cox proportional hazards model was used to examine relationship between work stress and suicidal ideation. Considering gender and age differences in the association between work stress and suicidal ideation, the data were stratified by gender and age groups. Results During 289 706 person-years of follow-up, suicide ideation was identified in 3 460 participants. For male workers, high job demands and lack of reward were associated with the risk of suicidal ideation in young adults and midlife decade group. Job insecurity was associated with the risk of suicidal ideation in midlife decade and middle-aged and older adulthood. Organizational injustice was associated with the risk of suicidal ideation in middle-aged and older adulthood. Discomfort in an organizational climate was associated with the development of suicidal ideation in all age groups. For female workers, organizational injustice and discomfort in an organizational climate were associated with the risk of suicidal ideation in early adulthood. Conclusion The results suggested that certain work stressors are risk factors of suicidal ideation. Gender and age differences in components of work stress associated with suicidal ideation were also observed.

The decoupling between the electrical conductivity and thermal conductivity is a crucial challenge to elevate the figure of merit of a given thermoelectric material. In this research, thermoelectric properties of the rare-earths sesquioxides added Bi-Sb-Te material has been investigated systematically. The electrical conductivity (σ) is increased by increase in carrier concentration due to progressive movement of reduced Fermi level deeper into the valance band. Meanwhile, an effective mass of the rare earth added BiSbTe composites has been increased and contributed to the resonant distortion in density of states (DOS), that gives rises to the enhancement of Seebeck coefficient (α). Owing to the increment of both factors (σ & α), a considerable enhancement in power factor of 14% was achieved for the 2 wt% added BiSbTe/(x-wt%) Nd2O3 composites. The low content addition of rare earth oxide particles are potentially acts as scattering centers for mid to long wavelength phonons and reduced the thermal conductivity by 7%. The effective decoupling of the electrical and thermal properties by rare earths sesquioxides (Nd2O3) provides a 15% enhancement in thermoelectric figure of merit, ZT for 2 wt% added BiSbTe/(x-wt%)Nd2O3 composites.

Atomistic defect engineering through the pulsed laser epitaxy of perovskite transition metal oxides offers facile control of their emergent opto-electromagnetic and energy properties. Among the various perovskite oxides, EuTiO3 exhibits a strong coupling between the lattice, electronic, and magnetic degrees of freedom. This coupling is highly susceptible to atomistic defects. In this study, we investigated the magnetic phase of EuTiO$_3$ epitaxial thin films via systematic defect engineering. A magnetic phase transition from an antiferromagnet to a ferromagnet was observed when the unit cell volume of EuTiO3 expanded due to the introduction of Eu-O vacancies. Optical spectroscopy and density functional theory calculations show that the change in the electronic structure as the ferromagnetic phase emerges can be attributed to the weakened Eu-Ti-Eu super-exchange interaction and the developed ferromagnetic Eu-O-Eu interaction. Facile defect engineering in EuTiO$_3$ thin films facilitates understanding and tailoring of their magnetic ground state.

Perfluorinated polymers are widely used in polymer electrolyte membranes because of their excellent ion conductivity, which are attributed to the well-defined morphologies resulting from their extremely hydrophobic main-chains and flexible hydrophilic side-chains. Perfluorinated polymers containing quaternary ammonium groups were prepared from Nafion- and Aquivion-based sulfonyl fluoride precursors by the Menshutkin reaction to give anion exchange membranes. Perfluorinated polymers tend to exhibit poor solubility in organic solvents, however, clear polymer dispersions and transparent membranes were successfully prepared using N-methyl-2-pyrrolidone at high temperatures and pressures. Both perfluorinated polymer-based membranes exhibited distinct hydrophilic-hydrophobic phase-separated morphologies, resulting in high ion conductivity despite their low ion exchange capacities and limited water uptake properties. Moreover, it was found that the capacitive deionization performances and stabilities of the perfluorinated polymer membranes were superior to those of the commercial Fumatech membrane.

The aim of this study was to evaluate prognostic factors including surgical, radiographic, and histopathologic analyses in anaplastic oligodendroglioma (AO) patients. We reviewed the electronic records of 95 patients who underwent surgery and were diagnosed with AO for 20 years. The primary endpoints were progression-free survival (PFS) and overall survival (OS). Univariate and multivariable analyses included clinical, histopathological, and radiographic prognostic factors. Subgroup analysis was performed in isocitrate dehydrogenase (IDH1/2)-mutant and 1p/19q-codeleted patients. The median PFS and OS were 24.7 months and 50.8 months, respectively. The 1-, 3-, 5-, and 10-year PFS were 75.8%, 42.9%, 32.4%, and 16.4%, respectively. Furthermore, the 1-, 3-, 5-, and 10-year OS were 98.9%, 76.9%, 42.9%, and 29.7%, respectively. The median PFS and OS of the IDH1/2-mutant and 1p/19q-codeleted patients were 54.2 and 57.8 months, respectively. In univariate analyses, young age, frontal lobe, weak enhancement, gross total resection (GTR), low Ki-67 index, 1p/19q codeletion, and IDH1/2 mutations were associated with a favorable outcome. In multivariable analyses, IDH1/2 mutation was related to better PFS and OS. In subgroup analysis, GTR was associated with favorable outcomes.

Several methods to synthesize poly(phenylene) block copolymers through the nickel coupling reaction were attempted to reduce the use of expensive nickel catalysts in polymerization. The model reaction for poly(phenylene) having different types of dichlorobenzene derivative monomers illustrated the potential use of cost-effective catalysts, such as NiBr2 and NiCl2, as alternatives to more expensive catalysts (e.g., bis(1,5-cyclooctadiene)nickel(0) (Ni(COD)2)). By catalyzing the polymerization of multi-block poly(phenylene) with NiBr2 and NiCl2, random copolymers with similar molecular weights could be prepared. However, these catalysts did not result in a high-molecular-weight polymer, limiting their wide scale application. Further, the amount of Ni(COD)2 could be reduced in this study by approximately 50% to synthesize poly(phenylene) multi-block copolymers, representing significant cost savings. Gel permeation chromatography and nuclear magnetic resonance results showed that the degree of polymerization and ion exchange capacity of the copolymers were almost the same as those achieved through conventional polymerization using 2.5 times as much Ni(COD)2. The flexible quaternized membrane showed higher chloride ion conductivity than commercial Fumatech membranes with comparable water uptake and promising chemical stability.

Aims To evaluate the bidirectional relationship between blood pressure (BP) and depressive symptoms using a large prospective cohort study. Methods Prospective cohort study was performed in 276 244 adults who participated in a regular health check-up and were followed annually or biennially for up to 5.9 years. BP levels were categorised according to the 2017 American College of Cardiology and American Heart Association hypertension guidelines. Depressive symptoms were assessed using Centre for Epidemiologic Studies-Depression (CESD) questionnaire and a cut-off score of ≥25 was regarded as case-level depressive symptoms. Results During 672 603.3 person-years of follow-up, 5222 participants developed case-level depressive symptoms. The multivariable-adjusted hazard ratios (HRs) [95% confidence interval (CI)] for incident case-level depressive symptoms comparing hypotension, elevated BP, hypertension stage 1 and hypertension stage 2 to normal BP were 1.07 (0.99–1.16), 0.93 (0.82–1.05), 0.89 (0.81–0.97) and 0.81 (0.62–1.06), respectively (p for trend p for trend p for trend Conclusions In this large cohort study of young and middle-aged individuals, higher BP levels were independently associated with a decreased risk for developing case-level depressive symptoms and depressive symptoms were also associated with incident hypertension. Further studies are required to elucidate the mechanisms underlying the bidirectional association between BP levels and incident depression.

Objectives Our study aimed to analyze the demographic and clinical characteristics of children and adolescents during their first visit to psychiatric outpatient departments for the management of suicidal ideation and behavior, and to compare the changes before and in 2012 or later. Methods This multicenter study was conducted at five university hospitals in a metropolitan area in South Korea. Medical records of patients aged 6-18 years were retrospectively reviewed from January 2009 to December 2016. Patients were analyzed by classifying them into suicidal and non-suicidal groups based on their visit to the hospital for management of suicidal ideation or suicide attempt and other mental problems, respectively. Results There were differences in the year of visit, diagnosis, education level, and referral sources between patients in the suicidal and non-suicidal groups. Multiple regression analysis was conducted based on the sex, education level, referral by school, and diagnosis of depression in patients in the suicidal group, which revealed significant association. Conclusion Suicide-related problems were significantly associated with the sex, education level, referral by school, and a diagnosis of depression in the patients. A well-connected referral system would be necessary for professional mental health management of high-risk children and adolescents.

Bismuth antimony telluride based thermoelectric (TE) materials have been intensively developed and synthesized using different mechanisms, for the room temperature TE applications. In particular, bismuth antimony telluride based TE alloys are very sensitive to deviations in their composition, and to contamination during the materials synthesis. Oxygen contamination during Bi-Sb-Te based materials synthesis is one of the critical factors that alters or diminishes thermoelectric-transport properties. Thus, in this study, how the oxide formation mechanism on the powder surface and bulks of p-type Bi0.5Sb1.5Te3 alloys affected the microstructural features and thermoelectric properties were elucidated quantitatively. While applying heat treatment (HT) to Bi0.5Sb1.5Te3 powder, the constituent elements interacted with the ambient atmosphere and formed a new oxide phase which acted as a barrier to carrier transport. At the initial stage (300 °C) of heat treatment, only the powder surface was oxidized due to the reaction of outer surface atoms with atmospheric air and moisture. While increasing in temperature during HT, this surface oxygen contamination diffused further inside the powder through the grain boundaries. More diffusion and spreading occurred throughout the matrix at 450 °C. The increment of oxygen content from 0.05 to 0.82 wt% drastically decreased the electrical conductivity by 67%, and thermal conductivity by 7% at the heat treatment temperature of 450 °C. This reduction behavior is mainly due to severe scattering of the carriers/phonons at the new formation of oxide (Sb2O3) phase near grain boundaries and within the matrix. At a glance, a small increase in the oxygen content wouldn't significantly influence the thermoelectric properties; however, at a certain level of oxide formation (0.82 wt%), severe effects could occur due to the intensified scattering or trapping of carriers by the oxide barrier formation at the grain boundaries.

This study identifies a profile of households that are likely to have stronger intentions to adopt two stormwater management practices, rain gardens and rain barrels. In particular, this study identifies the characteristics of likely adopters compared to persistent non-adopters. The data is from a survey in Columbia, Missouri with a 44% response rate. Results of multinomial logit models show that being female and living in a suburban area are important demographic factors that increase the likelihood that households plan on adopting both practices. This was also true for having positive attitudes towards the environment and believing that they need to protect water quality. Households that are more aware of the practices and perceive a need for technical knowledge to implement the practices are apt to be likely adopters. Since likely adopters are clearly different from persistent non-adopters, the direct comparison of these groups can facilitate targeted policies and informational campaigns.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that is cross-resistant to most β-lactam antibiotics. We investigated whether oxacillin, which is a β-lactam antibiotic, alone or in combination with punicalagin can affect the penicillin binding protein 2a (PBP2a)-mediated resistance of MRSA. Susceptibility testing of punicalagin with oxacillin was performed using the microdilution and checkerboard assay and the growth curve assay. Binding affinity of punicalagin for cell wall peptidoglycan (PGN) was confirmed by an increased concentration of PGN in bacterial cultures containing punicalagin. The level of PBP2a was analyzed by western blotting. Punicalagin exhibited antimicrobial activity in the viability assay and increased the susceptibility of MRSA to oxacillin. PGN interfered with the antimicrobial activity of punicalagin and prevented the synergistic activity of punicalagin and oxacillin. Increasing the concentration of punicalagin and maintaining a constant concentration of oxacillin resulted in synergistic suppression of the expression of the mec operon (mecA, mecI, and mecR1). The production of PBP2a was suppressed by the addition of punicalagin to oxacillin. Our findings demonstrate that punicalagin potentiates the effect of oxacillin on MRSA by reducing the transcription of mecA (a gene marker for methicillin resistance), which resulted in a reduced level of PBP2a. Keywords: MRSA, Punicalagin, PBP2a, β-lactam, Synergistic

Objective In this study, the relationship between occupational stress and suicidal ideation was investigated, focusing on gender differences among Korean employees. Methods Cross-sectional data for 53,969 workers were collected at Kangbuk Samsung Hospital health screening centers. Risk of suicidal ideation was assessed using a self-reported questionnaire examining suicidal ideation during the past year. Occupational stress was measured using 24 items of the Korean Occupational Stress Scale-Short Form (KOSS-SF). Logistic regression analysis was employed to estimate the odds ratios and 95% confidence intervals of the relationships between suicidal ideation and components of occupational stress. Results In multivariable-adjusted models, all job stress contributed to increased risk of suicidal ideation in males. Most subscales, except insufficient job control and organizational system, were risk factors of suicidal ideation in females. Further adjustments for depression markedly attenuated this relationship. However, the effects of insufficient job control and lack of reward on suicidal ideation remained significant in males, and interpersonal conflict remained significant in females. Conclusion The results suggest that occupational stress plays a significant role in increasing risk of suicidal ideation through elevation of depressive symptoms. Gender differences in components of occupational stress associated with suicidal ideation were also observed.

The oxidative stability of membranes constructed from a composite of pristine sulfonated poly(arylene ether sulfone) and cerium was investigated by conducting an accelerated oxidative-stability test at the open-circuit voltage (OCV). The membranes were analyzed in situ through OCV and impedance measurements, cyclic voltammetry, and linear-sweep voltammetry to monitor the electrochemical properties during the stability test. Although the high-frequency resistance of a composite membrane was slightly higher than that of a pristine membrane because of the exchange of protons from the sulfonic acid with cerium ions, the composite membrane maintained its potential for much longer than the pristine membrane. The effect of the cerium ions as radical scavengers was confirmed by analyzing the drain water and chemical structure after operation. These post-operation analyses confirmed that cerium ions improved the oxidative stability of the hydrocarbon-based polymer during fuel-cell operation. It is clear that the cerium-based radical scavengers prevented chemical degradation of the polymer membrane as well as the electrode in terms of hydrogen cross-over, polymer-chain scission, and the electrochemical surface area, while they rarely diffused outward from the membrane.

Increasing urbanization has led to increasing impermeable surfaces and use of lawn care products. Phosphorous (P) is a major pollutant in freshwater systems, leading to eutrophication, harmful algal blooms and hypoxia. An important source is runoff from urban areas so reducing use of P fertilizers by homeowners would be helpful. This study examines the use of two alternative fertilizer sources in an urbanizing watershed in the Midwest, organic fertilizer/composted manure and P-free fertilizer. A mail survey of households was conducted, resulting in a 44% effective response rate. The adoption rates were relatively high (31% and 23% respectively) compared to those found in previous work for rain gardens and rain barrels. Probit regression results found that adoption of both practices was higher among those who tested their soil, knew the watershed concept, and spent more than 10 hours per month gardening. Results for use of composted manure imply that adopters do not view this as fertilizer, which may result in buildup of P levels in the soil over time. Respondents who indicated that water quality was more important than economic development were more likely to use P-free fertilizers. Significant demographic factors for organic fertilizer were somewhat surprising; those with two years of college were more likely to adopt than those with a four-year degree and those with household income of $50,000 - 75,000 were more likely to adopt than those with an income of $75,000 - 100,000. No demographic factors were important for P-free fertilizers.

This study explores factors affecting adoption of two stormwater management practices, rain gardens and rain barrels. Mail survey data from Columbia, Missouri indicate adoption rates of 3.12 percent (rain gardens) and 7.47 percent (rain barrels). This unique dataset enables us to distinguish among nonadopters using knowledge levels, and to investigate the effect of practice-specific barriers. Clustered multinomial logistic regressions reveal serious gardeners are more likely to adopt both practices. Specific barriers differ by practice and type of nonadopter. Adding practice-specific barriers increased pseudo R2 values from 0.12 to 0.22 for rain gardens and from 0.13 to 0.26 for rain barrels.

Multi-block copolymers containing a partially fluorinated hydrophobic moiety (F-PE) are synthesized for application as alkaline membrane fuel cells (AMFCs). The partially fluorinated monomer is synthesized by palladium-catalyzed Suzuki coupling, and quaternary ammonium groups are introduced after selective chloromethylation of the hydrophilic blocks. TEM investigation of the block copolymers show well-defined hydrophilic-hydrophobic phase separation behavior, resulting in high anion conductivity. In particular, the partially fluorinated hydrophobic blocks are stable even after immersing into a 1 M KOH solution because the hydrophobicity of the fluorine moiety excludes hydrophilic nucleophiles, which are the main sources of chemical degradation of AEMs. Although the hydrophilic domains are slightly degraded under harsh alkaline conditions, the F-PE survives at room temperature in a 1 M KOH solution for 720 h. F-PE membranes result in an AMFC performance of 310 mA cm−2 at 0.6 V and 70 °C.